Aqueous Ions Flashcards
what is a Bronsted-Lowry acid
- proton donor
what is a Bronsted-Lowry base
- proton acceptor
what happens when metal aqua ions enter water
- one of the water ligands loses a H⁺ ion
- [Fe(H₂O)₆]³⁺ + H₂O → [Fe(H₂O)₅(OH)]²⁺ + H₃O⁺
what does the acidity of metal complexes depend on
- the charge on the central metal ion
- the higher the charge, the higher the charge density so the more polarised the O-H bond so the more H⁺ ions you will find in the solution
what is a Lewis acid
- electron pair acceptor
what is a Lewis base
- electron pair donor
what do the aqueous ions look like in a solution
- Cu²⁺ - blue [Cu(H₂O)₆]²⁺
- Fe²⁺ - green [Fe(H₂O)₆]²⁺
- Fe³⁺ - brown [Fe(H₂O)₆]³⁺
- Al³⁺ - colourless [Al(H₂O)₆]³⁺
aqueous ions with excess OH⁻ observations
- Cu²⁺ - NVC (blue ppt)
- Fe²⁺ - NVC (green ppt)
- Fe³⁺ - NVC (brown ppt)
- Al³⁺ - ppt redissolved (colourless) [Al(H₂O)₂(OH)₄]
- Ag⁺ - brown ppt (AgOH)
aqueous ions with dropwise OH⁻ observations
- Cu²⁺ - blue ppt [Cu(H₂O)₄(OH)₂]
- Fe²⁺ - green ppt [Fe(H₂O)₄(OH)₂]
- Fe³⁺ - brown ppt [Fe(H₂O)₃(OH)₃]
- Al³⁺ - white ppt [Al(H₂O)₃(OH)₃]
aqueous ions with dropwise NH₃ observations
- Cu²⁺ - blue ppt [Cu(H₂O)₄(OH)₂]
- Fe²⁺ - green ppt [Fe(H₂O)₄(OH)₂]
- Fe³⁺ - brown ppt [Fe(H₂O)₃(OH)₃]
- Al³⁺ - white ppt [Al(H₂O)₃(OH)₃]
aqueous ions with excess NH₃ observations
- Cu²⁺ - deep blue solution [Cu(H₂O)₂(NH₃)₄]²⁺
- Fe²⁺ - NVC (green ppt)
- Fe³⁺ - NVC (brown ppt)
- Al³⁺ - NVC (white ppt)
aqueous ions with CO₃²⁻ observations
- Cu²⁺ - green-blue ppt (CuCO₃)
- Fe²⁺ - green ppt (FeCO₃)
- Fe³⁺ - effervescence + brown ppt (Fe(H₂O)₃(OH)₃)
- Al³⁺ - effervescence + white ppt (Al(H₂O)₃(OH)₃)
aqueous ions with Cl⁻ observations
- Cu²⁺ - yellow-green solution [CuCl₄]²⁻
- Ag⁺ - white ppt (AgCl)
equation for reaction between 2+ metal ion and OH⁻ / NH₃ dropwise
- [M(H₂O)₆]²⁺ (aq) + 2OH⁻ (aq) → [M(H₂O)₄(OH)₂] (s) + 2H₂O (l)
- [M(H₂O)₆]²⁺ (aq) + 2NH₃ (aq) → [M(H₂O)₄(OH)₂] (s) + 2NH₄⁺ (aq)
equation for reaction between 3+ metal ion and OH⁻ / NH₃ dropwise
- [M(H₂O)₆]³⁺ (aq) + 3OH⁻ (aq) → [M(H₂O)₃(OH)₃] (s) + 3H₂O (l)
- [M(H₂O)₆]³⁺ (aq) + 3NH₃ (aq) → [M(H₂O)₃(OH)₃] (s) + 3NH₄⁺ (aq)
equation for reaction between 2+ metal ion and CO₃²⁻
- [M(H₂O)₆]²⁺ (aq) + CO₃²⁻ (aq) → MCO₃ (s) + 6H₂O (l)
equation for reaction between 3+ metal ion and CO₃²⁻
-[M(H₂O)₆]²⁺ (aq) + 3CO₃²⁻ (aq) → 2[M(H₂O)₃(OH)₃] (s) + 3CO₂ (g) + 3H₂O (l)
what does amphoteric mean?
- it can act as a base and an acid
equation for reaction between [Al(H₂O)₃(OH)₃] and excess OH⁻
- [Al(H₂O)₃(OH)₃] (aq) + OH⁻ (aq) → [Al(H₂O)₂(OH)₄]⁻ (s) + H₂O (l)
equation for reaction between Cu²⁺ and excess NH₃
- [Cu(H₂O)₄(OH)₂] + 4NH₃ (aq) → [Cu(H₂O)₂(NH₃)₄]²⁺ (s) + 2H₂O (l) +2OH⁻
